I have an American Standard Heat Pump unit that was installed in 2001 (model #twe049e13fb0). When the weather is cold and the unit starts up in the AM there is a load moaning noise coming out of unit(inside unit).The colder it is the loader it gets, to the point you can here it through the whole house. There is no noise when its summer and you use the A/C. Unfortunately this only started after we had to have compressor changed. The tech that did job is very reputable but is struggling trying to fix our problem. This has been going on for sometime because in So. Ga. you use A/C more than heat so it just drags on. The unit when installed oringinally had one of those heat recovering systems on it and he thought that might have some effect on it but have shut off water to system and disconnected pump on it so its basically no working. One other thing about noise is that has the sound of some type of turbine whine, a moaning whine. Sorry about odd description of noise only way to describe it.
Thanks for looking any suggestions would be greatly appreciated!